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jeffrow68

Actual Ride Report..PD Pumper Carb

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Following is an actual ride report. History:  I purchased the cheap Chinese PD pumper carb and made all the necessary modifications and tuning as detailed by others here (Mixxer, NEODS, Ricky,etc) and tested it against a PWK Clone (OKO) on my modified 230 with full EO exhaust, 67mm BBR piston, Terry Miller porting and ST2.0 cam. After much tuning and a nice gift from NEODS (replacement jet nozzle) I was very happy with the PD clone pumper compared to my well performing PWK clone.  Not sure how good the OKO PWK is or how good it could be since it is a clone (this potential issue was highlighted previously) but all parts from Keihin fit the OKO.  So with who knows what jetting that really worked well on the OKO, I was happy as hell compared to the OEM carb.  I can't overemphasize how much of an improvement this carb is as compared to the OEM. 

The Chinese PD pumper that I bought was for my cheapskate friends stock uncorked 230. A nice investment for him at about $40 total with no adapters or additional cables needed. What I found really interesting was how well it worked on my modded 230, so much so that I bought a factory Keihin pumper carb for my 230.

This weekend was a test and tune weekend. I put the Chinese PD pumper on my friends bike...wow! It made a very noticeable improvement over the OEM carb. He was extremely happy and impressed with this small investment, although I did a lot of work to get it tuned. I highly recommend this for anyone with mechanical aptitude, probably the most bang/per buck yet.

I rode my 230 on Saturday with the PWK carb and I was really happy. I switched to the OEM 1978 XL250 pumper on Sunday. Initially I did not notice much difference between the two carbs. Pretty much splitting hairs. 

Sunday night revealed some issues with the Keihin pumper. It was mounted at an angle and the pump lever was contacting the shroud which was preventing it from actuating. Also, the plug that I slipped into the choke shaft had came out which caused air bypassing the jets. I fixed both of these issues and rode again today.

Today was a real eye opener. I am experiencing some real performance from this bike that I did not think was possible. Roll on throttle results in a nice wheelie. 1st, 2nd, and 3rd (with persuasion) wheelies. Cranks super easy, even hot. Idles super smooth. Throttle response is snappy. WOT pulls awesome. No dead spots or stumbles anywhere.

I have a few powerhouses in my stable of bikes, but none so rideable as this 230. Everything seems to be working together...the Fox shock, CRF150R forks (still too harsh), the engine, carb, seat height, Vulcanduro tire, CRF450 pegs, Rox risers in forward position, Scotts stabilizer. I feel a real test coming soon for this 230, maybe a National Enduro race or a local hare scramble race. I can't seem to stay off this bike, spending too much time practicing skills such as balancing,pivot turns, log jumps, riding up trees and pivoting, stoppies,etc etc etc. The only real issue is the LOUD ASS EO EXHAUST! My neighbors are hating on me at an unprecedented level. I wish I had a fix for this. Other than that, I am golden.

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Excellent report jeffrow... Thanks for sharing...

Personally I can't stand loud exhausts of any kind, for any reason, or any application.....

Lifelong performance addict... Builder... Tuner ...Rider.... Hate loud exhausts...

Love low, deep tones with growl.... 

Once loud comes into the picture, I'm out... Don't care one bit about power that comes with an obnoxious exhaust bite attached to it...

Could not be happier with my pro circuit exhaust.... Power , response, sound...

Just saying... 

 

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I've had other people comment that the Pro-Circuit on mine had a nice sound. Nice and throaty and less noise than the factory without the baffle. One of the guys that mentioned this rides behind me a lot on single track on a factory bone stock 230. He's a better rider than me but I got more power so it works pretty good in the end.

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You may think of a yoush  header muffler when riding by houses horseback riders super quite. Sound  and tone like big bore no tin can rattle sound. Fit and finish is number 1. also there is a cheap way to buy one off amazon.

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15 hours ago, jeffrow68 said:

Following is an actual ride report. History:  I purchased the cheap Chinese PD pumper carb and made all the necessary modifications and tuning as detailed by others here (Mixxer, NEODS, Ricky,etc) and tested it against a PWK Clone (OKO) on my modified 230 with full EO exhaust, 67mm BBR piston, Terry Miller porting and ST2.0 cam. After much tuning and a nice gift from NEODS (replacement jet nozzle) I was very happy with the PD clone pumper compared to my well performing PWK clone.  Not sure how good the OKO PWK is or how good it could be since it is a clone (this potential issue was highlighted previously) but all parts from Keihin fit the OKO.  So with who knows what jetting that really worked well on the OKO, I was happy as hell compared to the OEM carb.  I can't overemphasize how much of an improvement this carb is as compared to the OEM. 

The Chinese PD pumper that I bought was for my cheapskate friends stock uncorked 230. A nice investment for him at about $40 total with no adapters or additional cables needed. What I found really interesting was how well it worked on my modded 230, so much so that I bought a factory Keihin pumper carb for my 230.

This weekend was a test and tune weekend. I put the Chinese PD pumper on my friends bike...wow! It made a very noticeable improvement over the OEM carb. He was extremely happy and impressed with this small investment, although I did a lot of work to get it tuned. I highly recommend this for anyone with mechanical aptitude, probably the most bang/per buck yet.

I rode my 230 on Saturday with the PWK carb and I was really happy. I switched to the OEM 1978 XL250 pumper on Sunday. Initially I did not notice much difference between the two carbs. Pretty much splitting hairs. 

Sunday night revealed some issues with the Keihin pumper. It was mounted at an angle and the pump lever was contacting the shroud which was preventing it from actuating. Also, the plug that I slipped into the choke shaft had came out which caused air bypassing the jets. I fixed both of these issues and rode again today.

Today was a real eye opener. I am experiencing some real performance from this bike that I did not think was possible. Roll on throttle results in a nice wheelie. 1st, 2nd, and 3rd (with persuasion) wheelies. Cranks super easy, even hot. Idles super smooth. Throttle response is snappy. WOT pulls awesome. No dead spots or stumbles anywhere.

I have a few powerhouses in my stable of bikes, but none so rideable as this 230. Everything seems to be working together...the Fox shock, CRF150R forks (still too harsh), the engine, carb, seat height, Vulcanduro tire, CRF450 pegs, Rox risers in forward position, Scotts stabilizer. I feel a real test coming soon for this 230, maybe a National Enduro race or a local hare scramble race. I can't seem to stay off this bike, spending too much time practicing skills such as balancing,pivot turns, log jumps, riding up trees and pivoting, stoppies,etc etc etc. The only real issue is the LOUD ASS EO EXHAUST! My neighbors are hating on me at an unprecedented level. I wish I had a fix for this. Other than that, I am golden.

LOL, it's a blaster exhaust. 

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It's too bad that the knock off PD pumpers aren't just a little bit better out of the box....

Not everyone wants to find and rebuild a vintage PD Pumper....

And not everyone wants to do the finish work on a knock off carb either...

But if the knock offs were just a bit better... The jetting is super close... The needle is adjustable and pretty much spot on with the clip in the 4th notch...

Nobody would have to bother with buying jets or rebuilding carbs or anything .... Just do a 40 dollar carb swap and have the best/simplest carb and power upgrade for next to no expense...

So close... Yet not....

 

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This would be great easy cheap swap for power. As we both know me after close to 50 years modding motos. Somethings that are supposed to work just need more work then part cost. That is how the ball rolls on dirt bikes. Im just happy you guys have another option to the PWK carb. I wont be changing my two motos with PWKs. As the work I did was too much to change again.For new guys that want to mod what a great job on new mod.

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4 hours ago, mixxer said:

It's too bad that the knock off PD pumpers aren't just a little bit better out of the box....

Didn't you and Neods buy the knockoff of the knockoff.  I wonder if the genuine OKO is better quality.

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This would be great easy cheap swap for power. As we both know me after close to 50 years modding motos. Somethings that are supposed to work just need more work then part cost. That is how the ball rolls on dirt bikes. Im just happy you guys have another option to the PWK carb. I wont be changing my two motos with PWKs. As the work I did was too much to change again.For new guys that want to mod what a great job on new mod.

Yes +1 if you got a PWK already, keep it on there.
The 37-39 year old XL PD Pumpers are usually almost at least dirty, Both of mine have. One so extremely dirty, the slide did not move at all.
A carb kit for both and a lot of meticulous labor to clean things up so keep that in mind when purchasing Genuine OEM

Still cheaper than PWK if you don't need a carb larger than a 29mm.
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1 hour ago, Baja Rambler said:

Didn't you and Neods buy the knockoff of the knockoff.  I wonder if the genuine OKO is better quality.

I don't know if OKO makes the PD Pumper copy... I just searched for xl250 carb..  Caltric was the shop I bought mine from off eBay...

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1 hour ago, adnohguy said:


Yes +1 if you got a PWK already, keep it on there.
The 37-39 year old XL PD Pumpers are usually almost at least dirty, Both of mine have. One so extremely dirty, the slide did not move at all.
A carb kit for both and a lot of meticulous labor to clean things up so keep that in mind when purchasing Genuine OEM

Still cheaper than PWK if you don't need a carb larger than a 29mm.

One thing I like better on PWK carb way smaller more easy to remove ,less moving parts to fail. Still great option pumper carb with great results

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43 minutes ago, mixxer said:

I don't know if OKO makes the PD Pumper copy... I just searched for xl250 carb..  Caltric was the shop I bought mine from off eBay...

OK, sorry, I was thinking of the PWK copy from mid Atlantic trials that Chuck posted.  

http://www.mid-atlantictrials.com/Copies.html

These pumpers seem to have suddenly appeared out of nowhere.  Maybe quality will improve in the future.

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I hit the link to the trials site...didn't see any pumper carbs available... So maybe OKO hasn't copied the PD...

The funny thing to me is I have no idea WHY these PD pumper carb copies are being manufactured...

Unless they are putting them on newly manufactued bikes and scooters around the rest of the world... And then decided to sell them aftermarket too...

 

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26 minutes ago, mixxer said:

I hit the link to the trials site...didn't see any pumper carbs available... So maybe OKO hasn't copied the PD...

The funny thing to me is I have no idea WHY these PD pumper carb copies are being manufactured...

Unless they are putting them on newly manufactued bikes and scooters around the rest of the world... And then decided to sell them aftermarket too...

 

I wonder if they put them on those three-wheeled dump truck/taxi vehicles with the ZS engine to give them the extra push.  They could be pretty anemic without it.

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I wonder if they put them on those three-wheeled dump truck/taxi vehicles with the ZS engine to give them the extra push.  They could be pretty anemic without it.


No that couldn't be the issue, there made/ built by the finest craftsmen in Asia. The attention to detail is exceptional.
After all they they supply those same engines to AJP I am told.
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Is the body casting the same size on these PD carbs between the XL250 & 500?  Inlet and outlet? Slide diameter?  With only the bore being a different size?  

What are the differences between these two carbs?

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On 9/4/2017 at 9:54 PM, jeffrow68 said:

The Chinese PD pumper that I bought was for my cheapskate friends stock uncorked 230. A nice investment for him at about $40 total with no adapters or additional cables needed. What I found really interesting was how well it worked on my modded 230, so much so that I bought a factory Keihin pumper carb for my 230.

This weekend was a test and tune weekend. I put the Chinese PD pumper on my friends bike...wow! It made a very noticeable improvement over the OEM carb. He was extremely happy and impressed with this small investment, although I did a lot of work to get it tuned. I highly recommend this for anyone with mechanical aptitude, probably the most bang/per buck yet.

I rode my 230 on Saturday with the PWK carb and I was really happy. I switched to the OEM 1978 XL250 pumper on Sunday. Initially I did not notice much difference between the two carbs. Pretty much splitting hairs. 

Sunday night revealed some issues with the Keihin pumper. It was mounted at an angle and the pump lever was contacting the shroud which was preventing it from actuating. Also, the plug that I slipped into the choke shaft had came out which caused air bypassing the jets. I fixed both of these issues and rode again today.

Today was a real eye opener. I am experiencing some real performance from this bike that I did not think was possible. Roll on throttle results in a nice wheelie. 1st, 2nd, and 3rd (with persuasion) wheelies. Cranks super easy, even hot. Idles super smooth. Throttle response is snappy. WOT pulls awesome. No dead spots or stumbles anywhere.

OK...... I appreciate this info and am trying to follow along here and in the monster previous thread which makes my brain ache......

1. Chinese PD pumper is cheap and new but can require a good bit of tweaking ==> on uncorked bike with good results and on Mixxer's modified bike with good results. That build is summarized here: http://bit.ly/2j5wtrk

2. OKO PWK clone is new, more expensive ==> works well on your modified bike

3. OEM 1978 XL250 pumper (is the same as the Keihin pumper?) tend to be worn and getting rare ==> on your modified bike and you now think it is even better than the OKO PWK clone?

Mixxer has commented on the condition of old XL250 pumpers... did you actually buy a new one ("factory Keihin pumper carb") or a used one?

Not sure I want to try the artisinal recrafting of the eBay item that Mixxer and others did. Too many projects. I would like to just buy an OKO and put it on my uncorked bike.

Advice on carb size would be appreciated. I mostly ride tight trails at 6000 feet and up.

Would I need a manifold adapter kit or other parts?

Edited by RedMesa

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Question about choke removal. My bikes sit overnight in the frost and snow, sometimes even in August in CO. They get very cold. Thinking that choke removal is not a good option for this kind of operation?

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Red Mesa....  Replies will be soon... 

Little bit of stuff to do first...

In the meantime... A sexy headpipe pic.. lol

IMG_20170906_195533076.jpg

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